The officer who fatally shot Philando Castile, 32, has been charged with second-degree manslaughter. Here's what you need to know about the traffic stop gone wrong, which ended up live-streamed on Facebook. (Editor's note: This video has been updated.) (Monica Akhtar,Jenny Starrs,Gillian Brockell/The Washington Post)

Prosecutors in Minnesota said Wednesday that they had charged a police officer with second-degree manslaughter for fatally shooting Philando Castile during a traffic stop in a Twin Cities suburb over the summer.

The shooting’s aftermath was broadcast on Facebook Live by Diamond Reynolds, Castile’s girlfriend, footage that quickly spread across social media and cable news, making it one of the most high-profile fatal police shootings during the protests that have occurred across the country in recent years.

“Stay with me,” she said at one point in the video, even as Castile continued bleeding in the front seat.

John Choi, the Ramsey County attorney, said at a news conference in St. Paul, Minn., that Jeronimo Yanez, the officer who shot Castile, would also be charged with endangering the lives of Reynolds and her 4-year-old daughter, who was also in the car. These counts, along with the manslaughter charge, are all felonies.

“No reasonable officer knowing, seeing and hearing what Officer Yanez did at the time would have used deadly force under these circumstances,” Choi said at the news conference Wednesday morning. “I have given Officer Yanez every benefit of the doubt on his use of deadly force, but I cannot allow the death of a motorist who was lawfully carrying a firearm under these facts and circumstances to go unaccounted for.”

Yanez, who said he feared for his life at the time of the shooting, could face up to 20 years in prison and up to $40,000 in fines, according to the 10-page criminal complaint filed in Ramsey County District Court.

The complaint states that Yanoz pulled over Castile, 32, after seeing him driving on the night of July 6 and saying that he looked like a suspect in a convenience store robbery days earlier. Choi said Wednesday that Castile is not a suspect in the robbery.

Yanez pulled Castile over at 9:04 p.m., and less than a minute later, began firing the first of seven fatal shots into the car. One bullet hit the armrest between Castile and Reynolds, the complaint said, while another went through the driver’s seat and hit the backseat behind Castile. Reynolds’s 4-year-old daughter was in a car seat on the passenger side of the backseat.

Authorities said that they reviewed audio recordings from Yanez’s squad car as well as video footage of the stop in determining the timeline. In the complaint, prosecutors say that Yanez approached Castile’s car and told him about a problem with his brake light.

After Castile handed Yanez his insurance card, Castile then said: “Sir, I have to tell you that I do have a firearm on me.” Yanez, before Castile finished the sentence, put his hand on his holstered gun and calmly replied “Okay,” according to the complaint.

Seconds later, Yanez told Castile not to pull out his gun, to which Castile said, “I’m not pulling it out,” and Reynolds echoed the same message, the complaint said. Yanez then screamed, “Don’t pull it out” before pulling his own gun out and firing seven shots at Castile.

Philando Castile, right, with his mother, Valerie. (Family photo)

The complaint then quotes Reynolds’s statement made in the Facebook livestream that went viral after the shooting: “He killed my boyfriend.”

According to Choi, Castille’s final words were, “I wasn’t reaching for it.”

Choi said that Yanez gave contradictory statements about what happened. The county attorney called Yanez’s use of deadly force unjustified, noting that while Castile was armed at the time he was pulled over, he “never removed or tried to remove” the .40 caliber semiautomatic handgun in his pocket. Choi also said that at the time Castile was shot, his wallet contained his driver’s license and permit to carry a pistol.

An attorney listed for Yanez did not respond to a request for comment Wednesday. The executive director of the Minnesota Police and Peace Officers Association said the group was “disappointed” by the charges.

“Police officers in Minnesota and across the country face pressures of life and death situations daily,” Dennis Flaherty, executive director of the association, said in a statement. “No one can speak for Officer Yanez as to what he actually encountered and what he feared that evening. We hope all people can understand that and can refrain from judgment.”

Flaherty said his group expects Yanez to plead not guilty.

Choi said Castile’s relatives were told of the decision to pursue charges on Tuesday night, and they praised the decision during a separate news conference on Wednesday.

“The family is pleased with that recommendation,” Valerie Castile, his mother, said at her briefing, surrounded by other relatives. “We are here in solidarity, my family and I, to support that decision.”

She called on anyone who protests to do so peacefully, saying that “we want peace. We don’t want any protests to get outrageous.”

An attorney representing Castile’s family said that they also planned to file a civil lawsuit stemming from his death. The attorney, Glenda Hatchett, also said she believed this was the first time an officer in Minnesota has been charged for fatally shooting someone.

Police officers are rarely charged for deadly on-duty shootings. Between 2005 and 2014, 48 officers were charged for shootings, according to Philip M. Stinson, a criminologist at Bowling Green State University in Ohio who studies arrests of officers.

Since the beginning of 2015, 30 officers have been charged with murder or manslaughter due to an on-duty shooting, Stinson said, a tally that includes Yanez.

Stinson said his records dating back to 2005 show that Yanez is the first Minnesota officer charged for an on-duty shooting over that span. According to the Minneapolis Star Tribune, 153 people in Minnesota have died after physical encounters with police officers since 2000, and until Wednesday, no officer had been charged.

Choi opted to make a decision about charging Yanez on his own, rather than by using a grand jury, because he said that it would be best if he made the decision “and be directly accountable to the public.”

Judge Glenda Hatchett, representing the family of Philando Castile, says manslaughter charges against a Minnesota officer for the shooting death of the black motorist are an important first step in a "long journey." (Reuters)

At a news conference Wednesday, Choi said that he chose the second-degree manslaughter charge — less severe than a first-degree count or a murder charge — because he thinks it is “the highest, most provable offense.”

Castile’s death occurred in Falcon Heights, a suburb near both Minneapolis and St. Paul, the state capital, and involved an officer who belonged to the department in St. Anthony, another city in the area. After Castile’s death, demonstrators marched to the governor’s mansion in St. Paul, and Gov. Mark Dayton (D) apologized to Valerie Castile.

Dayton called the decision to charge Yanez “an important step toward the determination of justice in this awful tragedy.”

St. Paul Mayor Chris Coleman said in a statement that Choi “made one of the hardest decisions a prosecutor has to make,” and said that he believed Choi’s “decision was grounded in a thorough investigation of the facts and a deep commitment to upholding his public responsibility.”

Yanez and his partner, Officer Joseph Kauser, were both put on leave from the St. Anthony Police Department after the shooting. Kauser will not face any charges, Choi said. The complaint states that Kauser did not touch or remove his gun and and said he was surprised when Yanez opened fire.

In a statement, the city of St. Anthony said that it has “confidence that justice will be served” and that officials would not make “any comments that could hinder a fair and impartial determination” in the case. Mark Casey, the city manager, said Wednesday that Yanez remains on paid administrative leave.

Yanez will make his first court appearance Friday afternoon and plans to turn himself in, Choi said.

During a state investigation carried out by the Bureau of Criminal Apprehension, which probed the shooting before handing its findings over to Choi’s office, Yanez told officials that he thought he and others in the area faced mortal danger.

“At that point, I was scared and I was in fear for my life and my partner’s life,” he said, according to the complaint. “And for the little girl in the back and the front seat passenger.”

Yanez said he believed Castile was putting his hand around something during the encounter.

Castille’s death came during a particularly fraught moment nationwide, one that saw a spate of shootings by and of police. He was shot and killed a day after an officer in Baton Rouge fatally shot Alton Sterling, and these two shootings set off a series of protests nationwide.

The Post’s database of shootings by police shows that 13 people have already been fatally shot by officers in Minnesota so far this year, already exceeding the 12 such people killed by officers there during all of last year.

In another case that prompted protests, police in Minneapolis fatally shot Jamar Clark a year and a day before Choi announced the charges on Wednesday. Prosecutors said earlier this year that the officers involved would not face charges because they believed Clark was trying to grab one of their guns.

At a Nov. 16 news conference in St. Paul, Minn., Ramsey County attorney John Choi updated the public on the investigation into the fatal police shooting of Philando Castile, saying he found that Castille exhibited "absolutely no criminal intent." The officer, Jeronimo Yanez, has been charged with second-degree manslaughter for the shooting (The Washington Post)